Finishing machine for metal surfaces

ABSTRACT

A MICHINE FOR FINISHING THE SURFACE OF A BOLT BODY OR THE LIKE WHEREIN THE BOLT BODY IS INDEXED AXIALLY THROUGH A PLURALITY OF POSITIONS AND IN EACH POSITION THE SURFACE IS SUBJECTED TO A FINISHING OPERTION TO PRODUCE A FINISH WHICH CAN BE TERMED A &#34;DIMASKEEN&#34; FINISH. THE FINISHING OPERATION IS CARRIED OUT BY A NUMBER OF ABRASIVE RODS MOUNTED IN ROTATING SPINDLES WITH THE SPINDLES BEING POSITIONED FOR RECIPROCATING MOVEMENT IN DIRECTIONS RADIALLY OR PREPENDICULARLY TO THE BOLT BODY. A ROTATING DRIVE SHAFT ACTS THROUGH CAM MEAN TO RECIPROCATE THE SPINDLES ACCORDING TO A PREDETERMINED PATTERN. THE DRIVE SHAFT IS ALSO CONNECTED THROUGH A DRIVE ARTANGEMENT WHICH INTERMITTENTLY ROTATES A GEAR HELD AGAINST AXIAL MOVEMENT AND THREADEDLY ENGAGED WITH AN INDEX SPINDLE SO THAT THE INDEX SPINDLE WHICH GRIPS THE BOLT BODY IS INDEXED AXIALLY IN STEP-WISE MOVEMENTS.

Nov. 9, 1971 P. B. CROOP FINISHING MACHINE FOR METAL SURFACES 9Sheets-Sheet 1 Filed Jan. 8, 1969 FIGW INVENTOR PAUL B. CROOP ATTORNEYNov. 9, 1971 P, B, RQOP 3,618,265

FINISHING MACHINE FOR METAL SURFACES Filed Jan. 9. 1969 9 Shets-Sheet 2INVENTOR PA u/ 5. CROOP Nov. 9, 1971 P. B. CROOP 3,618,265

FINISHING MACHINE FOR METAL SURFACES Filed Jan. 8, 1969 9 Sheets-Sheet 8INVENTOR PA u. 5. CROOP ATTORN Y Nov. 9, 1971 P. B. CROOP FINISHINGMACHINE FOR METAL SURFACES 9 Sheets-Sheet 4,

Filed Jan. 8, 1969 INVENTO PA U1. 5 CRooP BY flzin /JEZ 7Q.)

ATTORN Nov. 9, 1971 P. B. cRooP 3,618,255

FINISHING MACHINE FOR METAL SURFACES Filed Jan. 8, 1969 98heecs-Sheet 62" PASS '/\|/{/ANGULAR TRAVEL INVENTOR PA UL B CRoop ATTORNEY Nov. 9.,1971 P. B. CROOP 3,618,265

FINISHING MACHINE FOR METAL SURFACES Filed Jan 8, l9 9 Sheets-Sheet 7I05 I04 INVENTOR PA UL B. CRooP Nov. 9, 1971 P. B. cRo 3,618,265

FINISHING MACHINE FOR METAII SURFACES Filed Jan. 8, 1969 9 Sheets-Sheet8 Y INVENTOR PAUL B. CRooP BY mom/$2 ATTO R N EY 2 PASS POSITiON Nov. 9,1971 P. B. cRooP FINISHING MACHINE FOR METAL SURFACES FiledJan. a, 19699 Sheets-Sheet f) ATTORNEY INVENTOR PA UL B. CRooP United States PatentOlfice 3,618,265 Patented Nov. 9, 1971 3,618,265 FINISHING MACHINE FORMETAL SURFACES Paul B. Croop, llion, N.Y., assignor to Remington ArmsCompany, Inc., Bridgeport, Conn. Filed Jan. 8, 1969, Ser. No. 789,894Int. Cl. B24b /00 US. Cl. 51--111 15 Claims ABSTRACT OF THE DISCLOSURE Amachine for finishing the surface of a bolt body or the like wherein thebolt body is indexed axially through a plurality of positions and ineach position the surface is subjected to a finishing operation toproduce a finish which can be termed a damaskeen finish. The finishingoperation is carried out by a number of abrasive rods mounted inrotating spindles with the spindles being positioned for reciprocatingmovement in directions radially or perpendicularly to the bolt body. Arotating drive shaft acts through cam means to reciprocate the spindlesaccording to a predetermined pattern. The drive shaft is also connectedthrough a drive arrangement which intermittently rotates a gear heldagainst axial movement and threadedly engaged with an index spindle sothat the index spindle which grips the bolt body is indexed axially instep-wise movements.

The invention relates to metal surface finishing machines to produce adamaskeen pattern surface. A step in the manufacturing of variousarticles includes imparting a desired finsh to a surface or surfaces ofthe article. A surface is generally finished by some form of a grindingoperation using an abrasive suitable to the surface material and to thefinish desired.

In the making of bolt bodies for firearms, it is desired to impart aparticular type of finish to a major portion of the body surface. Thisfinish can be generally described as a damaskeen finish and comprises apattern of swirls over the finished surface. An abrasive rod can bebrought into contact with portions of the bolt body surface while therod is being rotated. Formerly, after each finishing operation of aportion of the surface, it was necessary manually to move the bolt bodyso as to bring another portion of its surface into position with respectto the rotating abrasive rod. It was also necessary to retract theabrasive rod from its grinding position to permit movement of the boltbody to the next position relative thereto. The axial movement orindexing of the bolt body by hand and the manual reciprocating of anabrasive rod to and from its grinding positions consumed a considerableamount of time of a skilled operator. It was also necessary that theoperator pay constant attention to the consecutive finishing operationsto insure that the finished surface was acceptable. The manual indexingof the bolt body and of the abrasive rod was not satisfactory because ofthe large amount of time required to finish each bolt body, whichcorrespondingly increased the manufacturing costs, and thenon-uniformity of the appearance of finished bolt bodies.

One of the objects of the present invention is to provide a machine forimparting a damaskeen finish to the surface of a work piece.

Another of the objects of the present invention is to provide a machinefor finishing the surface of a work piece wherein both the work pieceand the abrasive finishing materials are automatically positioned foreach finishing operation.

Another of the obiects of the invention is to provide a damaskeenmachine for bolt bodies wherein the bolt body can be finished withoutany manual manipulation on the part of an operator.

According to one aspect of the present invention, a machine forfinishing the surface of a work piece may comprise a holder to retainthe work piece for axial movement. A plurality of spindles are mountedon the machine for reciprocating movement and extend perpendicularly tothe surface of the work piece being finished. Where the work piecesurface is cylindrical, the spindles extend radially from the work pieceand are spaced equidistantly about its circumference. There are meansfor moving the spindles inwardly toward the work piece surface into afinishing operation position and then retracting the spindles outwardlyupon completion of the finishing operation. Means are provided forindexing the work piece axially upon completion of a finishing operationand at the end of a traverse, to angularly index the work piece.

Other objects, advantages and features of the present invention will beapparent from the accompanying description and drawings, which aremerely exemplary.

In the drawings:

FLIG. 1 is a top plan view of the machine according to the presentinvention with a portion of the bolt body holder removed;

FIG. 2 is a side elevational view of the machine of FIG. 1; 5

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is a sectional view of the spindle and taken along the line 4--4of FIG. 1;

FIG. 5 is a portion of the view of FIG. 4 and shows the spindle in theretracted position and the abrasive rod being released from the clampingcollet;

FIG. 6 is a plan view of the cam for reciprocating the spindles;

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 4;

FIG. 8 is a sectional view taken along the line 8-8 of FIG. 3 andshowing the intermittent drive arrangement for the index spindle;

FIG. 9 is a sectional view taken along the line 9-9 of FIG. 8;

FIG. 10 is a roll-out sectional view taken along the line 10-10 of FIG.8;

FIG. 11 is a sectional view taken along the line 11-11 of FIG. 3 andlooking upwardly at the index spindle and drive shaft;

FIG. 12 is a top plan view of the bolt body holder and showing the boltbody in position therein;

FIG. 13 is a side elevational view of the bolt body holder and the topof the index spindle and showing the bolt body in indexed positions;

FIG. 14 is an overall perspective view of the bolt body whose surface isfinished with the machine of the present invention;

FIG. 15 is a sectional view taken along the line 1515 of FIG. 14;

FIG. 16 is a sectional view taken along the line 1616 of FIG. 13; and

FIG. 17 is a longitudinal sectional view of the upper end of the indexspindle and showing the structure therein for gripping the lower end ofthe bolt body.

Proceeding next to the drawing wherein like reference symbols indicatethe same parts throughout the various views, a specific embodiment ofthe present invention will be described in detail.

The machine for imparting a damaskeen finish to a bolt body according tothe present invention is indicated generally at 10 in FIGS. 1-3. A boltwhich is to be finished is indicated at 11 in FIG. 14 and comprises abolt body 12 and a handle 13. At the lower end of the bolt body thereare provided locking lugs 14."

The bolt 11 is retained in a work piece holder indicated generally at15. The bolt is inserted into socket 15. In its initial position, thelower end of the bolt bearing lugs 14 extends from the bottom of thefixture to be gripped by the socket of the index spindle in a manner tobe presently described.

As may be seen in FIG. 1, a plurality of spindles 21 are positionedradially about the bolt on the top of the machine 10. The spindles areillustrated in greater detail in FIGS. 3-5 and each carries an abrasiverod 22. Each spindle is capable of reciprocating motion in a directionradially of the bolt body 12. Rod 22 is preferably a rubberizedabrasive, sold under the name Cratex, a trademark of CratexManufacturing Co.

Spindle 21 comprises a spindle housing 23 mounted upon base 24. Base 24is slidably mounted upon guides 25 supported within the top surface 26of the machine frame. The undersurface of base 24 is provided with twolongitudinally extending grooves 27 which receive springs 28. A camroller 29 is rotatably mounted on shaft 30 in the underside of base 24.

The upper surface of base 24 is provided with longitudinally extendingslots 31, 32 within which are positioned cushion members 33 mounted onscrews 34. These cushion members 33 extend upwardly into correspondinggrooves 35 formed in the underside of spindle housing 23. It can be seenthat cooperating grooves 31 and 35 are slightly longer than cushionmembers 33 to permit some play between the spindle housing and the base.

In spindle housing 23, a tubular casing 36 is journalled at both ends bybearings 37 with both ends of the casing extending outwardly of thehousing 23. The rear end of casing 36 has a pulley 38 keyed thereon bykey 39 with the pulley being drivingly connected by drive belt 40 to anelectric motor 41.

Slidably mounted within tubular casing 36 for axial movement therein isa first tubular member 42 having a. forward end 43 and a rear end 44.The rear end 44' projects outwardly of the casing 36 as may be seen inFIG. 4. The inner diameter of tubular member 43 is such to closelyreceive the abrasive rod 22 with the rod being capable of axial movementtherein. A plunger 45 is urged by a spring 46 against the end of therod.

From forward end 43 of the tubular member 42, there extends outwardly athin walled extension 47 having a plurality of longitudinal slotstherein and a circumferential enlargement 48 at the outer end to definea collet to grip the rod 22. The collet 48 is engageable by the flaringend 49 of a second tubular member 50 which is slidably mounted aroundthe forward end of tubular member 42 and biased outwardly by a spring51. A second spring 52 is positioned between an inner shoulder 53 ontubular member 50 and an external shoulder formed on the end 43 oftubular member 42.

The movement of tubular member 50 within casing 36 is limited by anannular shoulder 54 movable in an annular space 55 formed at the outerend of tubular casing 36 by a nipple 56.

The anti-friction bearings 37 at the ends of tubular casing 36 aremaintained at a predetermined distance by a cylindrical bushing 57.

Extending rearwardly from base 24 is a bracket 5'8 to which is pivotallyconnected at 59 an arm 60 connected at its other end to a piston rod 61of a hydraulic cylinder 62. The arm 60 is split so as to straddle agroove 63 formed in the rear end 44 of tubular member 42. It will beapparent that actuation of hydraulic cylinder 62 will cause the arm 60to pivot and thereby reciprocate tubular member 42 within the spindle.

When the spindle is in the retracted position (FIG. 5) and the hydrauliccylinder 62 is actuated, tubular member 42 will be moved forwardly andcollet 48 will be disengaged from the flaring end 49 of tubular member50 whereby the resilient structure of collet 48 will release rod 22 foraxial movement under the force exerted by plunger 45 and spring 46.

The ends of tubular element which move in respect to each other may beenclosed by flexible bellows covers 64 as shown in FIGS. 4 and 5.

The reciprocating movement of the spindles 21 which causes each spindleto advance and to retract with respect to the bolt body is controlled bythe cam roller 29 and a circular cam 65 journalled in the machine bybearings 66 as may be seen in FIG. 3. Attached to the underside ofcircular cam 65 is a ring gear 67 engaged by a pinion gear 68 keyed tothe upper end of a drive shaft 69. Drive shaft 69 is journalled in avertical position in the machine as may be seen in FIG. 3 and is driventhrough a reduction drive 70 through a drive belt 71 and an electricmotor 72.

The circular cam 65 and its associated ring gear 67 is shown in greaterdetail in FIG. 6. The cam comprises a plurality of cam surfacescorresponding to the plurality of spindles. In the present embodimentthere are provided eight spindles which are equi-distantly spaced aboutthe eriphery of the bolt body. It is to be understood, however, that thenumber of spindles may vary and need not be restricted to the number ofspindles employed in the present embodiment.

An index spindle 73 is rotatably mounted within the machine for limitedaxial movement. On the upper end of index spindle 73 there is provided atubular extension 74 which is resiliently held in the position shown inFIG. 3 by an internal spring 75. The upper end of extension 74 is shownin greater detail in FIG. 17 and has an opening 76 with internal lips 77for receiving the lugs 14 on the bolt 11. The lips 77 serve to grip thelower end of the bolt and to move the bolt axially through its fixture18. Extension 76 is slidably mounted on the end of index spindle 73 withthe range of axial movement being limited by a pin 78 passing through anaxial slot 79 in the index spindle.

A flexible boot 80 may connect the outer end of tubular extension 73with a boss portion 81 of the machine through which the index spindlepasses.

A threaded section 85 is provided along the central portion of the indexspindle and meshes with a gear 86 which is restrained against axialmovement. It will be apparent that rotation of gear 86 will cause thethreaded portion 85, and thus index spindle 73, to move axially throughthe gear.

The lower end of index spindle 73 is journalled in a bearing 87 carriedin a bracket 88 attached to the machine frame at 89.

The axial movement of index spindle 73 indexes axially the bolt bodywithin the fixture 18. The intermittent rotation of gear 86 andtherefore the intermittent axial movement of index spindle 73 isaccomplished through an intermittent drive mechanism indicated generallyat 90 in FIG. 3 and driven by the rotating drive shaft 69.

The intermittent drive mechanism, as illustrated in FIGS. 3 and 8,comprises an indexing disk 91 having a plurality of spaced blocks 92 onits upper surface to define indexing slots or notches 93. A ring gear 94is attached to the underside of indexing disk 91 and meshes through agear train indicated generally at 95 with gear 86 engaging the indexspindle. The gear train 95 comprises shafts 96, 97, and 98 which arejournalled in the machine and have meshing spur gears thereon as shownin FIG. 10.

An eccentric 100 is keyed to the drive shaft 69 and rotates Within anopening 101 in an indexing arm 102. At one end of the indexing arm thereisprovided a pin 103 which is journalled in a block 104 with the blockbeing slidable between the legs 105 of a stationary bracket 106 attachedto the machine.

The other end of indexing arm 102 is similarly provided with a pin 107which is journalled within a block 108 slidable between the legs 109 ofa pivoting arm 110 which pivots about drive shaft 69.

Inner end of block 108 is tapered, as may be seen in FIG. 8, so thatthis block may slide into the indexing notches 93. The pin 107 'willdescribe the somewhat elliptical path 111, as shown in FIG. '8, as thedrive shaft 69 rotates. It will be apparent that the block 108 will bemoved into a notch 93 and, while engaged with this notch, will move theindexing disk in the direction of the arrow 112. When the indexing diskmoves through a 40 index angle, the block will be retracted from theindexing notch to be disengaged therefrom and moved rearwardly to engagethe next succeeding notch. With each movement of the indexing disk, thegear train will be correspondingly moved to intermittently rotate gear86. The rotation of gear 86, while being held against axial movement,will impart an axial movement to the index spindle 73.

In response to the described operation of the intermittent drive, theindex spindle 69 will be moved downwardly until twenty-three finishingoperations have been carried out by the spindles on the bolt bodysurface. This represents the limit of the downward axial movement of theindex spindle. At this point the drive motor 72 is stopped and thefixture is indexed automatically through an angle of 22 /2". Thismovement positions the bolt body at a new angle of 22 /2 so as tosubject other surface portions to the action of the abrasive rods in amanner as shown in FIG. 15. The main drive motor is then reversed andenergized so as to rotate the drive shaft in the opposite direction.This reversed rotation of the drive shaft will be transmitted throughthe intermittent drive assembly to index the index spindle in an axialmovement upwardly. Again, the bolt body part will be indexedtwenty-three times and at each dwell will be subjected to a finishingoperation.

When the predetermined number of operations have been carried out, themachine is stopped, the bolt is removed from the fixture and the machineis ready for recycling.

Thus, it can be seen that the bolt body is provided with a decoratedsurface produced by the action of an abrasive point, not unlike adraftsrnans electric eraser, on the metal surface. Each application ofthe abrasive point produces a concentric swirl on the surface. Amultiplicity of such applications are made in an overlapping uniformlygeometrically spaced arrangement so as to provide a highly decorativeeffect.

The machine of the present invention supports a cylindrical bolt body ina vertical position. In uniformly radially spaced relationship about thelongitudinal axis of the bolt body are eight automatically advanced andretracted rotating spindles each tipped with a suitable abrasive tool.At each advance of the eight spindles, eight spots or swirls are formedon the surface of the bolt body. The bolt body then successively indexesor feeds downwardly to each of twenty-three different vertically spacedstations at each of which eight more spots or swirls are formed on thebolt body surface. At the bottom of the stroke, the bolt body is rotated22 /2 about its axis and the process repeated with the bolt body beingindexed upwardly and with eight more sets of overlapping swirls beingformed at each of the twenty-three vertically spaced positions.

The surface of other than a round bolt, e.g., a relatively flat surface,can be finished by arranging the machine spindle as needed. The movementof a spindle should be approximately perpendicular or normal to thesurface being finished.

It will be understood that various details of construction andarrangement of parts may be made without departing from the spirit ofthe invention except as defined in the appended claims.

What is claimed is:

' 1. In a machine for finishing the surface of a work piece, a holder toretain the work piece for axial movement thereof, a plurality ofspindles extending perpendicularly to the surface of the work piecebeing finished, means for moving said spindles inwardly toward said workpiece surface in a finishing operation and moving said spindlesoutwardly upon completion of the finishing operation, and means forindexing said work piece stepwise axially in one direction uponcompletion of a finishing operation, said spindles being moved inwardlyin said finishing operation while said work piece is at rest during thestepwise rest period of said work piece until the length of the workpiece surface has been subjected to finishing operations, and means topivot said work piece about its longitudinal axis through apredetermined angle and then to index it axially in the oppositedirection, so as to produce an overlapping pattern of spaced decorativespots on the work piece.

2. In a machine as claimed in claim 1 with said work piece surface beingcylindrical, said spindles extending radially to said work piecesurface.

3. In a machine as claimed in claim 1 and a rod of abrasive materialmounted in each of said spindles with an end of said rod projecting fromthe spindle and to be moved into contact with the work piece surface.

4. In a machine as claimed in claim 3 and means on said spindles foradvancing step-wise the abrasive rod ends outwardly after eachcompletion of a finishing operation.

5. In a machine as claimed in claim 1 and comprising a drive shaftrotatably mounted in said machine and operatively connected to a powersource, said spindle moving means and said indexing means being operatedin response to the rotation of said drive shaft.

6. In a machine as claimed in claim 1 with said indexing meanscomprising an index spindle mounted for rotational and axial movement insaid machine, and means on an end of said index spindle for grippingsaid work piece to move axially the work piece therewith.

7. In a machine as claimed in claim 6 and comprising a drive shaftrotatably mounted in said machine and operatively connected to a powersource, and means operatively connecting said drive shaft and indexspindle for moving said index spindle intermittently in an axialdirection in response to the rotation of said drive shaft.

8. In a machine as claimed in claim 7 with said index spindle movingmeans comprising a threaded portion on said index spindle, a gear havinginternal threads meshing with said index spindle threaded portion andgear teeth about the periphery thereof, said gear being retained againstaxial movement, and means engaging said gear teeth for intermittentlyrotating said gear in response to the rotation of said drive shaft.

9. In a machine as claimed in claim 5 with there being a plurality ofbases slidably mounted on the machine and each spindle being mounted ona base, said spindle moving means comprising cam means responsive to therotation of said drive shaft for reciprocating said spindles.

10. In a machine as claimed in claim 9 with said cam means comprising acircular cam rotatably mounted in said machine and having a plurality ofcam surfaces corresponding to the plurality of spindles, gear means fordriving said circular cam from said drive shaft, and a cam follower oneach spindle engaging said cam surfaces for reciprocating said spindlein a predetermined sequence.

11. In a machine as claimed in claim 3 with said spindles eachcomprising an elongated tubular member for retaining the abrasivematerial rod, spring means for urging said rod outwardly toward the Workpiece surface, releasable means for gripping said rod in the retainedposition, and means for releasing said gripping means upon completion ofa finishing operation so that said rod can be urged outwardly by saidspring means.

12. In a machine as claimed in claim 9 with each spindle comprising ahousing mounted on said base, and a rotatable element journalled in saidhousing.

13. In a machine as claimed in claim 12 and comprising means on saidmachine for rotating said spindle rotatable elements.

14. In a machine as claimed in claim 12 with said spindle rotatingelement comprising a tubular casing journalled within said spindlehousing, a first tubular member slidably mounted within said tubularcasing for axial movement therein and for receiving a rod of abrasivematerial, both ends of said first tubular member projecting outwardly ofsaid tubular housing, resilient means on the end of said first tubularmember adjacent the Work piece for clamping the rod of abrasive materialin position, a second tubular member surrounding said first tubularmember and spring biased to hold said resilient clamping means inclamping position against the abrasive rod, and means on said spindlehousing for moving said first tubular member axially to disengage saidresilient clamp means whereby said rod is free for axial movement.

8 15. In a machine as claimed in claim 14 with said'first tubular membermoving means operatively connected to the other end of said firsttubular member.

References Cited UNITED STATES PATENTS 828,894 8/1906 Martin 51 1112,423,715 7/1947 Luboshez 51- 114 2,443,655 6/1948 Stupakoflf 77262,788,623 4/1957 Procter 51246 FOREIGN PATENTS 539,459 7/1955 Belgium77, 32.2

HAROLD D. WHITEHEAD, Primary Examiner US. Cl. X.R. 7726

